Means and net for slowing down and/or stopping the motion of a land vehicle

ABSTRACT

A device for impeding the motion of a land vehicle is provided including a net having a first and a second end wherein the ends are separated to provide an elongated net arranged for grabbing a motor vehicle. A first braking device and a second braking are provided. The first braking device includes structure for slowing down the motion of the vehicle, and the second braking device includes structure for further slowing down and stopping the motion of the vehicle. The first and second members of the first braking device are shorter in length than the first and second members of the second braking device, such that the first and second braking device function stepwise with the first braking device braking the net first, and the second braking device braking the net second. The net is also formed of warp elements defining a vehicle wheel engaging structure which extends around the wheel of the vehicle when the vehicle runs over the net.

FIELD OF THE INVENTION

The present invention concerns a net for slowing down and/or stoppingthe motion of a land vehicle.

BACKGROUND OF THE INVENTION

It is necessary in some circumstances to be able to stop a movingvehicle or to slow down its motion by expedients external to thevehicle. A situation like this may present itself e.g. when it becomesmandatory to stop a vehicle which its driver, for instance a fleeingtraffic offender, will not stop without compulsion. Another situation isthat in which it is desirable to slow down the motion of a vehicle thatis running off the paving and moving erratically, and to stop thevehicle in order to prevent damage.

It is known in prior art to use a so-called spiked mat in stopping avehicle. The spiked mat is a means provided with spikes which are fixedor may come loose, and intended to be laid across the roadway, itspurpose being to puncture the tires of the vehicle running over the mat.As the air escapes from the tires, the speed of the vehicle will slowdown because the rolling resistance of the tires increases greatly. Atthe same time, the steerability of the vehicle is impaired and it can nolonger be driven at high speed.

The problem encountered when using spiked mats is that the vehicle whichshould be stopped may continue even a long way after its tires have beenpunctured.

It is also a problem when using spiked mats that as a result of losingits steerability the vehicle may run off the road or, for instance,collide with meeting vehicles.

For preventing the vehicle from running off the road, it is known in theart to use various, fixed or loose, obstacles. Such obstacles may takethe form, for instance, of fences made of metal sections, timber,concrete or another equivalent solid material. It is also commonpractice to use for lighter objects to slow down motion and to cushionbumps on race tracks, straw bales or other kinds of padding. Heavy andfirmly fixed obstacles are likely to injure the driver or the vehicle.Both kinds of obstacle are unsatisfactory as to their stopping power.

SUMMARY AND OBJECTS OF THE INVENTION

The object of the invention is to eliminate the drawbacks mentionedabove.

The object of the invention is further to provide a net for grabbing thevehicle which affords optimum grabbing of the vehicle and, at the sametime, grabbing of the car's wheels in order to prevent the vehicle fromgetting loose.

In order to accomplish this, the means of the invention for slowing downand/or arresting the motion of a land vehicle includes a net structurewith brake members as described below. The net of the invention forslowing down and/or arresting the motion of a land vehicle includes aheavy rope a foot rope and interesting warp elements as described below.

The means of the invention comprises an elongated net arranged to grabthe moving vehicle; and brake members connecting the net withsubstantially fixed anchoring points. As taught by the invention, saidbrake members comprise first brake members and second brake members; onefirst brake member and one second brake member have been disposed oneach end of the net; and the first brake member on either end of the nethas been connected to the near end of the net and the second brakemember has been connected to the opposite end of the net.

This crossing arrangement of the second brake members has the effectthat the vehicle to be stopped, after driving into the net, is bagged inthe net, whereby escape of the vehicle is efficiently prevented. Theelongated net has advantageously the form e.g. of a rectangle, the brakemembers being connected to the end of the rectangle's short sides.

In an embodiment of the means, the brake members are arranged to operatestepwise; and the first brake members are members retarding the speed ofthe vehicle; and the second brake members are members further retardingthe speed and stopping the motion. Stepwise action is here understood tomean that action of the brake members commences at different times. Thebrake members may operate simultaneously at least part of the time, orthey may operate fully consecutively so that after one brake member hasoperated the other brake member begins to operate. The brake members maybe dimensioned for different braking forces, and their braking distancesmay also be different. The crossing arrangement of the brake members hasthe effect that when a vehicle has driven into the net the first brakemembers begin to operate in the first step and furnish at least themajor part of the braking force. At a certain stage the second brakemembers begin to operate, thus joining the braking event. Since thesecond brake members have been attached crosswise on both ends of thenet, the vehicle will be bagged in the net. The vehicle stops as soon asthe second brake members have stopped their braking action and havebecome locked.

In an embodiment of the means the brake members are discardable fabricbrakes. A fabric brake is a member usually formed of one or severalribbons. The brake member may for instance be composed in that tworibbons have been woven or stitched together over a certain length. Thebrake member usually has two ends, on which draw members have beenformed. Pulling on the draw members will produce in the brake member asubstantially uniform braking force opposing the pull so that theribbons are forced to be torn apart. Brake members of this type havebeen described, for instance, in the Finnish patent application FI893910.

In an embodiment of the invention the first brake members are memberswhich open, and the second brake members are members which becomelocked. The characterization of members as members which open isunderstood to mean that in conclusion of their operation the first brakemembers altogether cease to operate, and release their grip. The secondbrake members become locked in conclusion of their retarding effect,whereby the braking force increases to great height in the end. Thelocking brake members may, for instance, be locking fabric brakes suchas are disclosed in the Finnish patent application FI 893910, which donot come open after having braked all the way to the end.

In an embodiment of the means the second brake members are fabric brakesin which the braking force has been graduated stepwise to increase toessentially great height on conclusion of braking. On the terminal endof a fabric brake may be provided a braking portion where the brakingforce is higher than that at the beginning of braking. For instance,when the brake members are hitched to tow hooks of cars, the ultimatelyactive braking force of the fabric brake may advantageously be higherthan the friction force of the anchoring cars against their base.

In an embodiment of the invention the brake members are hitched toanchoring points on immobile vehicles, for instance to tow hooks, and/orto fixing sites offered by the terrain, such as ground, trees, stubs,stones, or the like. When the brake members are hitched to anchoringpoints on vehicles, e.g. to tow hooks, a means is obtained which can berapidly set up for action. Additional anchoring points may be providede.g. on trees. It is equally possible to anchor the brake members tofixed anchoring points on the border of the roadway which have beenformed e.g. of fixing elements fixed in the concrete base.

In an embodiment of the invention the means comprises two nets, oneafter the other, which have been offset relative to each other in thelongitudinal direction of the nets a distance substantially equivalentto one half of the net's mesh diagonal. It is possible with two nets,one after the other, located immediately adjacent to each other andlaterally offset relative to each other so that the centre of each meshof one net coincides with a nodal point of the other net's warpelements, to ensure advantageous seizing of the vehicle in the net andholding on to the vehicle because the front corners of the vehicle willmore positively in every case push through one mesh of the net,whichever happens to meet the corner. It is obvious that any number ofnets, such as may be considered necessary, can be placed one after theother.

The means of the invention is used as a safety fence, e.g. on the sideof the track or roadway or placed in position across the driving lane tostop a vehicle.

The net for slowing down and/or stopping the motion of a land vehiclecomprises a head rope and a foot rope, both longitudinal to the net, andwarp strings therebetween forming the mesh of the net, and the mesh sizeof the net is substantially consistent with the size of the wheel of thevehicle to be slowed down or stopped. Ribbon-like material should inthis context be understood to mean e.g. slab-like or ropelike materialformed as well of yarn by weaving or formed of coherent material.

When the mesh size of the net is substantially consistent with the sizeof the vehicle's wheel, excellent seizing of the net on the vehicle, andespecially on its wheels, is achieved. The net behaves in such a waythat part of it is entrained under the vehicle and under its tires,whereby it will readily attach itself to the wear surface of the tireand, adherent thereto, will begin to wind itself along with the wheelaround the axle assembly and other undercarriage structures. Thisrenders the vehicle unable to extract itself from the net, even if itshould try to back out.

In an embodiment of the net, substantially all warp strings arepositioned at an oblique angle against the longitudinal direction of thenet. In this way advantageous seizing of the vehicle and wrapping of thenet around the vehicle and its parts are achieved, so that a maximum ofwarp strings participate in keeping the vehicle in the net. It is also afact that the meshes of the net will be advantageously positioned aroundthe corners of the vehicle.

In an embodiment of the invention the meshes have substantially theshape of a quadrangle, such as a parallelogram, square or rhombus,standing on its point in the vertical direction of the net, and thediagonal of the mesh substantially parallels the length direction of thenet. This shaping of the mesh of the net further promotes the windingand clinging of the net to the body of the vehicle, and to the wheels.When the net winds itself around the vehicle, the diagonal of the net'smesh becomes positioned substantially parallel to the tire's plane ofrotation and the sides of the mesh (e.g. parallelogram, square orrhombus), in such manner that they tend to adhere to the surface of thetire, whereby the wheel easily slips through the mesh of the net.

In an embodiment of the invention the length of the mesh diagonal is 0.5to 1.0 m, suitable 0.6 to 0.9 m, and advantageously 0.7 to 0.8 m. Thetires of passenger cars trafficking the highways, the outer diameters ofthe wheels are equal in size within rather narrow limits, and it istherefore possible to design the means of the invention in such a waythat it is fit, as to its dimensioning, with greatest possible coverage,for use in stopping any passenger car that is in motion on the road.

In an embodiment of the net the height of the net is 1.2 to 2.2 m,suitably 1.5 to 2.0 m, and advantageously 1.6 to 1.9 m. The heights ofthe front part of passenger cars trafficking the highways are similarwithin rather close limits, and it is therefore possible to design themeans of the invention so that it is fit, as to its dimensioning, withthe greatest possible coverage, for use in stopping any passenger carthat is in motion on the road. The height of the net in relation to thedriver's eye level is also a psychologically significant variable: it ispossible by means of various net heights to regulate the reaction of thedriver after he has perceived the net. If the head rope of the net is atsubstantially greater height than the driver's eye, it is probable thatthe driver will commence panic braking once he sees the net because inhis subconscious he fears that the net will hurt him. If on the otherhand the head rope of the net is located below the driver' s eye level,he is not frightened by the net and instead believes himself able topush through. In this manner he can in fact be enticed to drive into thenet. Selection of the net height can be made according to conditions ineach particular instance.

In an embodiment of the net the length of the net is 6 to 9 m,advantageously 7 to 8 m. The length of the net is advantageouslyequivalent to the width of a two-lane roadway.

In an embodiment of the net the net is made of polyester fabric ribbonand/or of nylon fabric ribbon. With these materials the net will beadvantageous as to tensile strength and light weight.

In an embodiment of the net the head rope and foot rope form on the endsof the net a first hitching loop and a second hitching loop. Thehitching loop is advantageously large enough to allow the brake membersto pass through. In that case no particular, e.g. metallic, fixingclamps etc. are needed which might damage the side of the vehicle afterthe net has become wound around the vehicle.

In an embodiment of the net the difference between the lengths in thedirection of the net of the first and second fixing loops issufficiently equal to one half of the mesh diagonal. When using twoidentical nets consecutively close to each other, one may achieve theoffset between the two nets in the amount of half a mesh by the simpleexpedient that the fixing loops differing in size in the proportionmentioned are superimposed and the net is fixed in place, whereby thedesired offset will take place.

In an embodiment of the net the warp elements of the net are knotted.Joining of the net's warp elements with each other may naturally equallybe accomplished by any other suitable joining method, e.g. by sewing,weaving, knitting, etc.

In an embodiment of the net warp element has been formed of two ribbonswoven or stitched together upon each other.

In an embodiment of the net the crossing point of the warp elements hasbeen formed in that the superimposed ribbons have been separated at thepoint of crossing and the crossing warp element passes between theribbons.

In an embodiment of the net each warp element forms a reciprocatinglymeandering figure, and the warp elements interlock at the corner points.This interlocking of the weft threads may be accomplished by anysuitable joining method, e.g. by knotting, stitching, pushing onethrough the other, etc.

In an embodiment of the net the warp has between nodal points beenrotated 180° about its longitudinal axis. When the warp elements aremade of two superimposed and mutually joined ribbons and the warpelements are in a suitable manner interlocked by knotting, saidlongitudinal rotation affords the advantage that when the superimposedribbons of the warp are torn apart, the ribbons do not end upconstituting two separate nets, and the strength of the whole net cannotbe substantially impaired even if such rupture should occur.

The net of the invention is used as safety fence, e.g. on the side ofthe roadway or, placed across the roadway, to stop a vehicle.

It is an advantage of the invention that the vehicle can be stoppedindependent of its driver's actions.

It is an advantage of the invention that the vehicle can be stopped in acontrolled manner, without causing any danger.

Further, thanks to the invention, the vehicle can be stopped on apre-determined, comparatively short distance.

It is furthermore an advantage of the invention that it will not damagethe vehicle nor injure its driver or passengers.

It is furthermore an advantage of the invention that it is easily andrapidly set up in operating condition.

It is furthermore an advantage of the invention that it can be devisedto be light of its weight and transportable with ease, and presentinggood operating efficiency at the same time.

It is an advantage of the invention that the vehicle that has beenstopped with the means cannot get free by backing. It follows that avehicle once stopped cannot escape.

It is an advantage of the invention that with the invention is achievedparticularly effective grabbing of the vehicle in the net so that anychance of getting free from the net is inhibited.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following the invention is described in detail, referring to theattached drawing, wherein:

FIG. 1 presents schematically in elevational view, an embodiment of themeans of the invention,

FIG. 2 presents another embodiment of the means of the invention,

FIG. 3 presents the embodiment of FIG. 2, in a situation of itspractical application, and in top view,

FIG. 4 presents the embodiment of FIG. 1, placed across the roadway, and

FIGS. 5, 6 and 7 present the embodiment of FIG. 4 of the invention invarious stages of its use, seen from above.

FIG. 8 presents schematically an embodiment of the net of the invention.

FIG. 9 presents two nets as in FIG. 8, placed one after the other.

FIG. 10 presents, viewed obliquely from above, a passenger car in asituation in which another embodiment of the net of the invention hascaught on the car.

FIG. 11 shows the left front corner of the car of FIG. 10, viewed frombelow, and

FIG. 12 shows a detail of a third embodiment of the net of theinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

In FIG. 1 is depicted, schematically and in elevational view, anembodiment example of the means of the invention, comprising a net 1 forgrabbing a vehicle in motion, and brake members 2 which connect thegrabbing member with fixed anchoring points 3. The net 1 is an elongatednet, between its both ends and the anchoring points 3 having beenprovided the brake members 2 to connect the net and the anchoring pointswith each other. The net 1 has been stretched in readiness foroperation, with vertical supports 6. The brake members 2 are attached oneither side of the net 1, at the ends of its short sides.

The brake members 2 comprise first brake members 4 for slowing down themotion of the vehicle and second brake members 5 for further slowingdown and stopping the motion of the vehicle. The brake members 2 arediscardable fabric brakes in which the braking force is produced byripping off each other parts of fabric webbing which have been securedto each other. The first brake members 4 are here opening-type fabricbrakes which release on exhaustion of their braking capacity. The secondbrake members 5 are discardable fabric brakes which are of the type thatbecomes locked on exhaustion of the braking capacity. A locking-typefabric brake may, for instance, be such as is described in the Finnishpatent application FI 893910.

On either end of the elongated net 1 there is one set of first brakemembers 4 and one set of second brake members 5. The first brake members4 on either end of the net are connected to the nearest end of thenet 1. The second brake members 5 on either end of the net are connectedto the opposite end of the net. Thus, the first brake member 4 on theleft of the net is connected to the left end of the net. The secondbrake member 5 on the left of the net is connected to the right end ofthe net. The first brake member 4 on the right of the net is connectedto the right end of the net. The second brake member 5 on the right ofthe net is connected to the left end of the net.

In FIG. 2 is depicted another embodiment example of the means of theinvention, wherein the elongated net has been formed to constitute afencelike structure, and which comprises a plurality of brake members 2,disposed with suitable spacing along the net 1. The brake members 2 areat one end anchored to the ground, in any suitable manner.

In FIG. 3 is depicted, as viewed from above, the safety fence of FIG. 2,in an operating situation in which a racing car has driven off thetrack. The brake members 2 have slowed down the motion of the car andhave finally become locked, preventing it from dashing any farther in anundesirable direction, e.g. into the mass of spectators.

In FIG. 4 the means of FIG. 1 has been installed across the roadway. Thefirst brake members 4 and the second brake members 5 have been hitchedto anchoring points 3 on immobile vehicles, said anchoring points beingtow hooks in this instance. Furthermore, a fixing ribbon has beencarried from the tow hook to a tree, for additional fixing.

In FIG. 5 the means of FIG. 4 is depicted as seen from above. Thevehicle A is in the situation of the figure just about to run into thenet. As the car proceeds in the net, the distension forces increaseuntil the brake members 4 and 5 begin to operate. The first brakemembers 4 are opening-type fabric brakes, and the second brake membersare locking-type fabric brakes. Their braking forces have been designedto be appropriate in view of the purpose, taking into account the weightof the vehicle to be stopped and the required braking distance.

In FIG. 6 the first brake members 4 operate and furnish braking force.At this stage the second brake members 5 also begin to operate. Sincethe second brake members disposed on both sides of the net have beeninstalled crosswise in relation to the net, as seen from above, the netbegins to form a bag around the vehicle A.

In FIG. 7 the vehicle A has proceeded even farther, whereby the firstbrake members 4 have completely opened and braking takes place by effectof the second brake members 5. The vehicle stops when the brakingcapacity of the second brake members is exhausted and they becomelocked. Since the second brake members had been attached to the ends ofthe net in crosswise fashion, as seen from above, the net ultimatelyshapes itself into a bag which encloses in itself at least part of thevehicle and eliminates its chances of getting out of the net.

In an operating situation of the means of the invention, a passenger carweighing 900 kg drives into a net arranged as shown in FIG. 5, with aspeed of 150 km/h. The totalled braking force of the first brake membersis 8000N and their operating distance, 10 m. The totalled braking forceof the second brake members is 16000N and their operating distance, 50m. The vehicle stops after it has proceeded about 60 m, and the highestdeceleration is about 2 g.

In FIG. 8 is shown a horizontal, elongated net 1 made of ribbon-likematerial, for grabbing a moving land vehicle. The net 1 comprises a headrope 7 and a foot rope 8, both longitudinal to the net, and between themwarp elements 9, which form the meshes 10 of the net. The mesh size ofthe net is substantially consistent with the size of the wheel of thevehicle that is to be stopped or slowed down. The net has been made offlexible material which readily wraps itself around the vehicle.

All warp elements 9 of the net 1 are positioned at an oblique angleagainst the longitudinal direction of the net.

The meshes 10 of the net are substantially shaped like a square orrhombus standing on its point. The diagonal 11 of the net substantiallyparallels the longitudinal direction of the net.

The length of the diagonal 11 of the mesh 10 is 0.5 to 1.0m, suitably0.6 to 0.9m, and advantageously 0.7 to 0.8 m. The mesh size of the net 1is then substantially consistent with the size of the wheel of thevehicle that has to be stopped or slowed down, whereby when the net haswrapped itself around the vehicle the wheel of the vehicle readilysticks to the wheel, and the wheel will go through the mesh 10.

The height of the net 1 is 1.2 to 2.2 m, suitably 1.5 to 2.0 m, andadvantageously 1.6 to 1.9 m. When the height of the net is about 1.8 m,it is best suited for stopping a passenger car.

The length of the net is 6 to 9 m, advantageously 7-8 m. The net willthen extend in place across the road when stretched over the wholebreadth of a two-lane roadway.

The net 1 is made of polyester fabric ribbon and/or nylon fabric ribbon.Such ribbon is particularly appropriate for material of the net becauseit is a light material with high tensile strength which can be packed ina small space.

The head rope 7 and foot rope 8 form on the ends of the net 1 a firsthitching loop 12 and a second hitching loop 12 and a second hitchingloop 13.

In the embodiment of FIG. 9 the means comprises two consecutive nets1¹,1², which are in principal similar to the net which was described inconnection with FIG. 8. The nets 1¹,1² have in the longitudinaldirection of the net been offset in relation to each other to a distancewhich is substantially consistent with one half of the diagonal 11 ofthe net's mesh.

In both nets the difference between the length in the direction of thenet of the first hitching loop 12¹,12² and the length in the directionof the net of the second hitching loop 13¹,13² substantially equals onehalf of the diagonal 11 of the mesh 10. When such nets are superimposedone after the other as shown in the figure, a combination of two nets isobtained which looks denser. The corners of the vehicle will at alltimes be well positioned to pass through a mesh of one net or the other.

It is clearly seen in FIG. 10 how the embodiment of the net formed astaught by the invention behaves when a vehicle has got into the net in astopping arrangement in which the net 1 has on both ends been connectedto fabric brake members operating stepwise as shown in FIG. 2. Theheight of the net 1 is about 1.5 m, length about 7.5 m; and length ofthe diagonal of the mesh 5 about 0.75 m. The meshes 10 of the net 1 haverhomboid shape. In a typical situation the net 1 has wrapped itselfaround the front part of the car. The foot rope 8 runs under the car'sbumper and the head rope 7 runs over the bonnet. The front corners ofthe car have pushed through meshes of the net, and the car is firmlygripped by the net. The net curves along the front flanks of the cardown under the car, obliquely backward and inward, as a result of theaforesaid disposition of the brake members. The net has partly goneunder both front wheels of the car.

In FIG. 11 is seen the car of FIG. 10, viewed from below. Typically, amesh 10 of the net 1 coincides with a wheel of the car. If in thissituation the car tries to drive forward or rearward, the warp elements9 will become adherent to the wheel and, together with the wheel, wrapthemselves around the axle of the wheel. When this has happened, it isimpossible for the car to get free from the net any more. The net mustbe cut away from the car in most instances.

In FIG. 12 is shown an advantageous way in which the warp elements 9 ofthe net 1 are joined by knotting. The warp element 9 has been formed oftwo ribbons 14,15 stitched together, one upon the other. The crossing ofthe warp elements 9¹,9² has been formed in that the superimposed ribbons14,15 have been separated at the crossing and the crossing warp elementpasses through between the ribbons 14,15. Both warps 9¹,9², of whichonly part is shown here, form a meandering, reciprocating configuration,and the warp elements 9¹,9² have been joined at the angulation points sothat first the warp element 9² passes through between the ribbons 14¹and 13² of the warp element 9¹ at the crossing point, where these havebeen separated, and thereafter similarly the warp element 9¹ passesthrough between the ribbons 14² and 15² of the warp element 9².Moreover, the warp element 9² has been rotated 180° about itslongitudinal axis on the run between its angulation points.

The invention is not confined exclusively to concern the embodimentexamples presented in the foregoing: numerous modifications are feasiblewhile keeping within the scope of the inventive idea defined by theclaims.

I claim:
 1. A device for impeding the motion of a land vehicle,comprising:a net having a first end and a second end, said ends beingseparated to provide an elongated net arranged for grabbing a movingvehicle; first brake means including a first end brake member attachedto said net first end and attached to a substantially fixed anchoringpoint on a first end side of said elongated net and a second end brakemember attached to said net first end and attached to a substantiallyfixed anchoring point on a second end side of said elongated net forbraking said net; and second brake means including a first end brakemember attached to said net first end and attached to said substantiallyfixed anchoring point on said second end side of said elongated net anda second end brake member attached to said net second end and attachedto said substantially fixed anchoring point on said first end side ofsaid elongated net for braking said net, said first brake means includesmeans for slowing down motion of said vehicle, and said second brakemeans includes means for further slowing down and stopping motion ofsaid vehicle, said first brake means first end brake member and secondend brake member are of a length which is shorter than said second brakemeans first brake member and second brake member allowing said first andsecond brake means to function stepwise with said first brake meansbraking said net first and said second brake means braking said netsecond.
 2. Device according to claim 1, wherein said brake members arediscardable brake elements formed of fabric.
 3. Device according toclaim 1 wherein said first brake members are of an opening type and thesecond brake members are of the locking type.
 4. Device according toclaim 1 wherein said second brake means brake members are formed offabric in which the braking force has been stepwise arranged to increaseto substantially great height in conclusion of the braking.
 5. Deviceaccording to claim 1 wherein said brake members are hitched to anchoringpoints on immobile vehicles and/or to fixing points afforded by theterrain, including ground, trees, stumps or stones.
 6. Device accordingto claim 1 wherein a plurality of nets have been placed one after theother.
 7. A net for slowing down and/or stopping motion of land vehiclesat an interdiction site, comprising:a first vertical support disposed atone side of said interdiction site; a second vertical support disposedat another side of said interdiction site; a head rope connected to eachvertical support and extending therebetween; a foot rope connected toeach support and extending therebetween; warp elements extending betweensaid head rope and said foot rope to define vehicle wheel engaging meansincluding warp elements sized for extending around a wheel of thevehicle as the vehicle runs over said foot rope, said foot rope beingmaintained between said vertical supports adjacent ground surface atsaid interdiction side, said vehicle wheel engaging means including eachwarp element extending at an oblique angle with respect to alongitudinal direction of said net, said warp elements havingsubstantially a shape of a quadrangle, such as a parallelogram square orrhombus.
 8. Net according to claim 7 wherein a length of the diagonal ofthe mesh is 0.5 to 1.0 m.
 9. Net according to claim 7 wherein the heightof the net is 1.2 to 2.2 m.
 10. Net according to claim 7 wherein thelength of the net is 6 to 9 m.
 11. Net according to claim 7, whereinsaid net is made of polyester fabric ribbon and/or nylon fabric ribbon.12. Net according to claim 7, wherein the head rope and foot rope formon the ends of the net a first hitching loop and a second hitching loop.13. Net according to claim 12, wherein a difference between the lengthin the direction of the net of the first hitching loop and the length inthe direction of the net of the second hitching loop is substantiallyequal to one half of the length of the diagonal of the mesh.
 14. Netaccording to claim 7 wherein the warp elements of the net are jointedtogether by knotting.
 15. Net according to claim 7 wherein the warp hasbeen formed of two superimposed ribbons joined by weaving or stitching.16. Net according to claim 15, wherein the crossing of warp elements hasbeen formed in that the superimposed ribbons have been separated at thecrossing point and the crossing warp element passes through between theribbons.
 17. Net according to claim 7 wherein each warp element forms ameanderingly reciprocating configuration, and that the warp elements arejoined together at the angulation points.
 18. A net for slowing downand/or stopping motion of land vehicles at an interdiction site,comprising:a first vertical support disposed at one side of saidinterdiction site; a second vertical support disposed at another side ofsaid interdiction site; a head rope connected to each vertical supportand extending therebetween; a foot rope connected to each support andextending therebetween; warp elements extending between said head ropeand said foot rope to define vehicle wheel engaging means including warpelements sized for extending around a wheel of the vehicle as thevehicle runs over said foot rope, said foot rope being maintainedbetween said vertical supports adjacent ground surface at saidinterdiction side, said vehicle wheel engaging means including each warpelement extending at an oblique angle with respect to a longitudinaldirection of said net, warp element being rotated 180° about itslongitudinal axis between angulation points.